The effect of nonequilibrium boundary layers on compressor performance

The paper investigates the effect of nonequilibrium behavior of boundary layers on the profile loss of a compressor. The investigation is undertaken using both high fidelity simulations of a midheight section of a compressor blade and a reduced order model, MISES. The solutions are validated using experimental measurements made in the embedded stage of a multistage low speed compressor. The paper shows that up to 35% of the suction surface boundary layer of the compressor blade exhibits nonequilibrium behavior. The size of this region reduces as the Reynolds number is increased. The nonequilibrium behavior was found to reduce profile loss in cases of attached transition and raise loss where transition occurs through separation